Vitamins E and C pretreatment prevents ovariectomy-induced memory deficits in water maze

We investigated whether the pretreatment with vitamins E (alpha-tocopherol) and C (ascorbic acid) would act on ovariectomy-induced memory deficits in Morris water maze tasks. Adult female Wistar rats were divided into three groups: (1) naive (control), (2) sham (submitted to surgery without removal of ovaries) and (3) ovariectomized. Thirty days after surgery, they were trained in the Morris water maze in order to verify ovariectomy effects both on reference and working memory tasks. Results show that ovariectomized rats presented impairment in spatial navigation in the acquisition phase, as well as in the time spent in target quadrant and in the latency to cross over the location of the platform in test session, when compared to naive and sham groups (controls), in the reference memory task. Ovariectomy did not affect performance in the working memory task. Confirming our hypothesis, ovariectomized rats pretreated for 30 days with vitamins E and C had those impairments prevented. We conclude that ovariectomy significantly impairs spatial reference learning/memory and that pretreatment with vitamins E and C prevents such effect. Assuming this experimental memory impairment might mimic, at least in part, the cognitive deficit sometimes present in the human condition of lack of reproductive hormones, our findings lend support to a novel therapeutic strategy, based on vitamins E and C, to cognitive impairments in post-menopausal women.     

Global behavioral variation: A test of differential-K

Despite Rushton’s path-breaking work into evolutionary forces affecting life history traits, not many attempts at operationalizing the differential-K spectrum at the level of countries or racial groups have been made so far. We report the construction of a “national K” factor from country-level behavioral variables. This K factor is closely related to country-level intelligence (“g”), operationalized by a composite score of IQ and scholastic achievement. We further demonstrate relationships of both g and K with measures of current environment and hypothesized evolutionary antecedents. Whereas K is predicted most powerfully by intelligence, log-transformed GDP (lgGDP) and skin reflectance, g is predicted by skin reflectance, lgGDP, cranial capacity, and a measure of evolutionary novelty.     

County-level IQ and fertility rates: A partial test of Differential-K theory

Human intelligence (IQ) correlates with a number of important life outcomes ranging from mortality and morbidity to social rank and status. Noticeably absent from the literature, however, has been a unifying framework from which to examine why IQ should correspond to so many seemingly disparate outcomes. Rushton’s Differential-K theory represents a theoretical perspective capable of accounting for the role of IQ in understanding human flourishing. We tested predictions suggested by Differential-K theory by examining the association between IQ at the aggregate level and two life-history variables: parental investment and fertility rates. Our results provide tentative support for some of the predictions of Differential-K theory.     

Apodemus sylvaticus (LOXT) is a suitable mouse strain for testing spatial memory retention in the Morris water maze

Information on the difference in cognitive function between laboratory and wild-caught mice is anecdotal and this question has not been systematically studied. Moreover, studying a wild-caught mouse strain per se may add information to the repertoire of mouse strains available. We aimed to study spatial memory in a wild mouse strain (Apodemus sylvaticus, AS) as compared to two individual laboratory mouse strains.Male AS (n = 20), CD1 (n = 19) and C57BL/6J mice (n = 19), 12–14 weeks old, were used in the experiments. The Morris water maze (MWM) was used for determination of spatial memory and time spent in the target quadrant at time points 5 (D5) and 12 days (D12) was evaluated. During the acquisition phase latency to reach the platform and path length to reach the platform was evaluated.Following four training days on day 5 (D5), time spent in the target quadrant was highest in AS > CD1 > C57BL/6J (P < 0.006). On day 12 (D12), time spent in the target quadrant was significantly higher in AS than in both other strains (P < 0.001).All animals learned the task and during the acquisition phase, latency to reach the platform as well as path length decreased significantly in AS.It is concluded that the AS is the most suitable strain for the evaluation of spatial memory in the MWM and is presenting with memory retention superior to laboratory mouse strains CD1 and C57BL/6J.     

The ameliorating effect of oroxylin A on scopolamine-induced memory impairment in mice

Oroxylin A is a flavonoid and was originally isolated from the root of Scutellaria baicalensis Georgi., one of the most important medicinal herbs in traditional Chinese medicine. The aim of this study was to investigate the ameliorating effects of oroxylin A on memory impairment using the passive avoidance test, the Y-maze test, and the Morris water maze test in mice. Drug-induced amnesia was induced by administering scopolamine (1 mg/kg, i.p.) or diazepam (1 mg/kg, i.p.). Oroxylin A (5 mg/kg) significantly reversed cognitive impairments in mice by passive avoidance and the Y-maze testing (P<.05). Oroxylin A also improved escape latencies in training trials and increased swimming times and distances within the target zone of the Morris water maze (P<.05). Moreover, the ameliorating effects of oroxylin A were antagonized by both muscimol and diazepam (0.25 mg/kg, i.p., respectively), which are GABA(A) receptor agonists. Furthermore, oroxylin A (100 microM) was found to inhibit GABA-induced inward Cl(-) current in a single cortical neuron. These results suggest that oroxylin A may be useful for the treatment of cognitive impairments induced by cholinergic dysfunction via the GABAergic nervous system.     

Effects of Sesame Street: A meta-analysis of children's learning in 15 countries

Sesame Street is broadcast to millions of children globally, including in some of the world's poorest regions. This meta-analysis examines the effects of children's exposure to international co-productions of Sesame Street, synthesizing the results of 24 studies, conducted with over 10,000 children in 15 countries. The results indicated significant positive effects of exposure to the program, aggregated across learning outcomes, and within each of the three outcome categories: cognitive outcomes, including literacy and numeracy; learning about the world, including health and safety knowledge; social reasoning and attitudes toward out-groups. The effects were significant across different methods, and they were observed in both low- and middle-income countries and also in high-income countries. The results are contextualized by considering the effects and reach of the program, relative to other early childhood interventions.     

Natural choice in chimpanzees (Pan troglodytes): Perceptual and temporal effects on selective value

In three experiments, four chimpanzees made choices between two visible food options to assess the validity of the selective value effect (the assignment of value to only the most preferred type of food presented in a comparison). In Experiment 1, we established that all chimpanzees preferred single banana pieces to single apple pieces before presenting the critical test. In this test two chimpanzees preferred a mix of one banana piece and one apple piece to a single banana piece when both banana pieces were approximately the same size, but two chimpanzees were indifferent between the two options, exhibiting the selective value effect. In Experiment 2, when the banana pieces in both options were more closely equated in size, the chimpanzees were biased to choose the single banana piece over the mixed array even though this was the smaller total amount of food. However, in Experiment 3, when we introduced longer intervals between each trial, the chimpanzees preferred the mixed set and thus the larger total amount of food. The results demonstrate that only some chimpanzees exhibit the choice pattern indicative of the selective value effect, and they do so only when item size is not carefully controlled and trials are presented quickly in succession. Thus, the behavior pattern originally labeled the selective value effect may actually be explained by a combination of chimpanzees’ sensitivity to small differences in preferred food amount and chimpanzees tendency to avoid less preferred foods that would delay the acquisition of further preferred food items.     

Politics, schadenfreude, and ingroup identification: The sometimes happy thing about a poor economy and death

Political campaigns are often characterized by the various events occurring that move the tide in favor of one candidate or another. Each event, depending on which candidate it favors or harms, produces either happiness or sadness for those who care about the outcome. This research examined whether such reactions would hold for events that are misfortunes for other people and even when they negatively affect society more broadly regardless of political party affiliation. Ingroup (i.e. political party) identification was examined as an important moderating variable. In four studies, undergraduate participants gave their emotional reactions to news articles describing misfortunes happening to others (e.g. poor economic news and house foreclosures). Party affiliation and the intensity of ingroup identification strongly predicted whether these events produced schadenfreude.     

The dependability of the general factor of intelligence: Why small, single-factor models do not adequately represent g

Floyd, Shands, Rafael, Bergeron and McGrew (2009) used generalizability theory to test the reliability of general-factor loadings and to compare three different sources of error in them: the test battery size, the test battery composition, the factor-extraction technique, and their interactions. They found that their general-factor loadings were moderately to strongly dependable. We replicated the methods of Floyd et al. (2009) in a different sample of tests, from the Minnesota Study of Twins Reared Apart (MISTRA). Our first hypothesis was that, given the greater diversity of the tests in MISTRA, the general-factor loadings would be less dependable than in Floyd et al. (2009). Our second hypothesis, contrary to the positions of Floyd et al. (2009) and Jensen and Weng (1994), was that the general factors from the small, randomly-formed test batteries would differ substantively from the general factor from a well-specified hierarchical model of all available tests. Subtests from MISTRA were randomly selected to form independent and overlapping batteries of 2, 4 and 8 tests in size, and the general-factor loadings of eight probe tests were obtained in each battery by principal components analysis, principal factor analysis and maximum likelihood estimation. Results initially indicated that the general-factor loadings were unexpectedly more dependable than in Floyd et al. (2009); however, further analysis revealed that this was due to the greater diversity of our probe tests. After adjustment for this difference in diversity, and consideration of the representativeness of our probe tests versus those of Floyd et al. (2009), our first hypothesis of lower dependability was confirmed in the overlapping batteries, but not the independent ones. To test the second hypothesis, we correlated g factor scores from the random test batteries with g factor scores from the VPR model; we also calculated special coefficients of congruence on the same relation. Consistent with our second hypothesis, the general factors from small non-hierarchical models were found to not be reliable enough for the purposes of theoretical research. We discuss appropriate standards for the construction and factor analysis of intelligence test batteries.     

Sources of Cognitive Exploration: Genetic Variation in the Prefrontal Dopamine System Predicts Openness/Intellect

The personality trait Openness/Intellect reflects the tendency to be imaginative, curious, perceptive, artistic, and intellectual - all characteristics that involve cognitive exploration. Little is known about the biological basis of Openness/Intellect, but the trait has been linked to cognitive functions of prefrontal cortex, and the neurotransmitter dopamine plays a key role in motivation to explore. The hypothesis that dopamine is involved in Openness/Intellect was supported by examining its association with two genes that are central components of the prefrontal dopaminergic system. In two demographically different samples (children: N = 608; adults: N = 214), variation in the dopamine D4 receptor gene (DRD4) and the catechol-O-methyltransferase gene (COMT) predicted Openness/Intellect, as main effects in the child sample and as a gene-gene interaction in adults.     

Reconsolidation and memory infidelity in Lymnaea

Lymnaea stagnalis were operantly conditioned to not perform aerial respiratory behaviour in a specific context (i.e. context-1). The memory for this learned response was reactivated 3 days later in context-1. During the 1 h reconsolidation period following memory reactivation, randomly picked snails were either maintained in context-1 or exposed to a new context (i.e. context-2). One hour later in the post-reconsolidation period, snails in context-1 were placed for 1 h in context-2 and vice-versa. In neither the hypoxic reconsolidation nor the post reconsolidation periods did snails receive a reinforcing stimulus when they opened their pneumostome. All snails were blindly tested for memory 24 h later period in context-2. Only those snails that had been exposed to context-2 during the reconsolidation period exhibited 'memory' for context-2. That is, memory infidelity was observed. Snails exposed to context-2 in only the post-reconsolidation period did not show memory for context-2. The immediate cooling of snails after their exposure to the new context in the reconsolidation period blocked the formation the implanted memory. Snails trained in context-1 and exposed to context-2 in the consolidation period only, also did not have memory for context-2. However, the memory for context-1 could still be recalled following successful implantation of the 'new' memory. All data presented here are consistent with the notion that during the reconsolidation process memory can be updated.     

Comparison of impulsiveness, venturesomeness and empathy (I7) structure in English and Spanish samples: Analysis of different structural equation models

The present study analyzed the factorial structure of the I₇ Impulsiveness questionnaire (Impulsiveness, Venturesomeness and Empathy) with a Spanish sample of 742 males and 1.075 females, through exploratory and confirmatory factorial analysis. In relation to the original English data, a three-factor structure showed global congruency coefficients of 0.92 and 0.94 for men and women. Venturesomeness had a modest congruency for males (0.83). A cross-validation analytical strategy showed that the 24-item I₇ was invariant only for the female sample. A subsequent exploratory factor analysis with 24 items showed a sound factor structure. The 24-item version showed the best and most robust structure and similar internal consistency coefficients in regard to the 54-item version. No important differences were founded between I₇ long and short versions with impulsiveness scales of ZKPQ, BIS-10 and SPSRQ.     

The preference for symmetry in flower-naïve and not-so-naïve bumblebees

Truly flower-naïve bumblebees, with no prior rewarded experience for visits on any visual patterns outside the colony, were tested for their choice of bilaterally symmetric over asymmetric patterns in a radial-arm maze. No preference for symmetry was found. Prior training with rewarded black and white disks did, however, lead to a significant preference for symmetry. The preference was not specific to symmetry along the vertical axis: a preference for horizontal symmetry was found as well. The results challenge the notion that a preference for bilateral symmetry is unlearned. The preference for symmetry was the product of non-differential conditioning.     

Testosterone and domain-specific risk: Digit ratios (2D:4D and rel2) as predictors of recreational, financial, and social risk-taking behaviors

Prenatal testosterone has important effects on brain organization and future behavior. The second-to-fourth digit length ratio (2D:4D), a proxy of prenatal testosterone exposure, has been linked to a wide variety of sexually differentiated dispositions and behaviors. We examine the relationship between digit length ratios (2D:4D and rel2, the length of the second finger relative to the sum of the lengths of all four fingers) and risk-taking behaviors across five domains: financial, social, recreational, ethical, and health. In a sub-sample of male Caucasians (ethnically homogeneous), lower rel2 was predictive of greater financial, social, and recreational risk-taking, whereas lower 2D:4D was predictive of greater risk-taking in two domains (social and recreational). In the full male sub-sample (ethnically heterogeneous), the only significant correlation was a negative association between 2D:4D and financial risk. A composite measure of risk-taking across all five domains revealed that both rel2 and 2D:4D were negatively correlated with overall risk-taking in both male sub-samples. No significant correlations were found in the female sub-samples. Finally, men were more risk-seeking than women across all five contexts.     

Differences in self-talk frequency as a function of age, only-child, and imaginary childhood companion status

In three studies, we examined differences in the frequency with which people report talking to themselves. Using a standardized measure of self-talk frequency, the Self-Talk Scale (Brinthaupt, Hein, & Kramer, 2009), we collected information about college student participants’ age, sex, and family configuration (i.e., only or sibling child), and whether they had an imaginary companion in childhood. In Study 1, significant differences in self-talk were found between different age groupings. In Study 2, children without siblings reported more self-talk than children with siblings. Finally, in Study 3, respondents who reported having an imaginary companion in childhood also reported significantly more self-talk than those who did not have an imaginary childhood companion. We discuss the self-regulatory and developmental implications of these results.     

IQ, skin color, crime, HIV/AIDS, and income in 50 U.S. states

In 50 U.S. states, we found a positive manifold across 11 measures including IQ, skin color, birth rate, infant mortality, life expectancy, HIV/AIDS, violent crime, and state income with the first principal component accounting for 33% of the variance (median factor loading = .34). The correlation with a composite of total violent crime was higher with skin color (r = .55), a more biologically influenced variable than with GDP (r = −.17), a more culturally influenced variable. These results corroborate and extend those found at the international level using INTERPOL crime statistics and at the county, provincial, and state levels within countries using local statistics. We interpret the cross-cultural consistency from an evolutionary life history perspective in which hierarchically organized traits culminate in a single, heritable, super-factor. Traits need to be genetically organized to meet the trials of life—survival, growth, and reproduction. We discuss brain size and the g nexus as central to understand individual and group differences and we highlight melanin and skin color as a potentially important new life history variable.     

Reading First kindergarten classroom instruction and students' growth in phonological awareness and letter naming–decoding fluency

This study investigated the role of the amount, content, and implementation of reading instruction provided by 17 kindergarten teachers in eight Reading First elementary schools as it related to students' progress (n = 286 students) on early reading assessments of phonological awareness and letter naming–decoding fluency. Children's phonological awareness and letter naming–decoding fluency grew significantly from fall to spring. On average, across the three 60 min observations, teachers provided over 30 min a day of phonological awareness and phonics instruction and 15 min a day of vocabulary and comprehension instruction. Global ratings of instructional quality revealed two implementation factors: explicit and individualized implementation and meaningful interactions around text. Hierarchical linear modeling revealed that the amounts of specific instructional content, as well as how this instruction was implemented, was related to students' letter knowledge and phonological awareness skill growth.